1972] 
Young — Hymenitis 
289 
The egg-adult developmental time is summarized in Table 1 and 
no difference was observed between sexes. 
Larval behavior 
All instars remain on the dorsal surfaces of leaves throughout their 
development in the field ; both feeding and resting activities are con- 
fined to dorsal leaf surfaces. First and second instars build thin 
silken mats for resting behavior; these mats are usually located near 
the center of the leaf. Larvae are never gregarious and this is cor- 
related with oviposition behavior (see below) ; larval densities sel- 
dom rise above 3 per individual host plant. Only one larva was found 
per leaf in sample of 33 plants bearing larvae. First to third instars 
appear very cryptically colored but the fourth to fifth instars are 
more conspicuous, owing to the very light green dorsal body surface 
accompanied by the lateral double striping pattern. But these larvae 
build a “nest” by curling in the proximal edges of large leaves of 
the host plant, and anchoring these in place with a few silken strands 
(Fig. 2-D). The larva builds a thick silken mat inside this en- 
closure, presumably as a resting site. The nest is seldom completely 
closed over but the curling in appears sufficient enough to render the 
larva inconspicuous in shadows created by the leaf edges. The third 
instar exhibits a form of nest-cleaning behavior in which pieces of 
accumulated excrement are taken up in the mandibles and tossed 
outside the nest. Foraging usually occurs on the same leaf as the 
nest, and when a leaf becomes about half eaten away, the larva 
abandons the next for another leaf and builds a new nest. As in 
earlier instars, the third instar always returns to the silken mat be- 
tween foraging episodes. First and second instars are strictly noc- 
turnal feeders, while the third instar feeds erratically day and night. 
First and second instars have the usual capacity to suspend them- 
selves from a leaf at the approach of a potential predator (such as 
an ant). Curiously, this behavior cannot be elicited by solely mechan- 
ical means. Later instars do not exhibit this behavior. 
Adult behavior 
Adult population densities at the study site are exceedingly low on 
a daily basis. It is therefore difficult to obtain quantitative data on 
patterns of adult activity. But oviposition sequences were observed 
on a total of 1 8 days at the study site, and presumably these involved 
several different females, although this cannot be confirmed until 
data are available on home range movements of adults. For exam- 
ple, a roost of several adults of clear wing ithomiines was found 
in lowland wet forest (Finca la Selva) at 4:30 PM on August 12, 
